Are you looking mostly for onroad performance? Sprinters are great I'm sure, but unless you've just got your heart set on one I would narrow things down right away by assuming those are better than many of the others you can find out about here. My Quigley with factory GM stabilitrac is great in the snow I think. Better than the Toyota Sequoia I used to own in my opinion.

For serious 4x4-ing, I would, personally, take a Ford conversion over a Sprinter factory 4x4 without hesitation. From what I have seen, the factory Sprinter 4x4s that are available in the US perform well in a variety of 4x4-ing tasks. But for heavy stuff--and this is just my opinion--I perceive the Fords as stronger and more capable. My two cents, and I am strictly firing blanks here. I don't want to start a "Ford v. Sprinter" shooting war. What's good for one person is not necessarily what's good for another, and if you want a Sprinter, then by all means, get a Sprinter, and enjoy the heck out of it. There are plenty of folks who did just that, and are very happy with their choices. I'm just tossing this out there as something to consider if it is helpful.

If you don't plan to hit aggressive and/or narrow overgrown trails, living space gained in a Sprinter would be very nice. Just depends on where and what kind of off roading you want to do. Lift and turning radius are also important especially with an EB Ford like mine. I've taken my EB on several OHV routes, something I'd never consider with a 4x4 Sprinter but there are miles of forest service trails that are Sprinter capable.

I think the op is asking if there's any differences between the '15 and '16 Sprinters with 4X4? not the differences in capabilities between 4X4 rigs. Maybe he can clarify....factory 4X4 became available on the sprinters in '15, don't think they changed much in '16, anyone have any other info on that? Other than that, find one that fits the budget, weather a full SMB buildout or a bare bones cargo for you to build out yourself. There's a few choices of upfitters out there nowadays. OP-where do you live? That might determine where you go to get the work done.